Multi-plate electrostatic chuck with ceramic base plate

Abstract

We provide an electrostatic chuck (ESC) for a substrate processing system having a multi-plate arrangement that handles high RF voltages. [Solution] The ESC200 comprises a top plate 202 made of ceramic to electrostatically clamp to the substrate, an intermediate layer 204 positioned below the top plate, and a base plate 206 made of ceramic positioned below the intermediate layer. The intermediate layer connects the top plate to the base plate.

Description

Technical Field

[0005] ,

[0006] ,

[0001] [Cross - Reference to Related Applications] This application claims the priority of U.S. Utility Patent Application No. 15 / 903,682, filed on February 23, 2018. The entire disclosure of the above application is incorporated herein by reference.

[0002] This disclosure relates to an electrostatic chuck of a substrate processing system.

Background Art

[0003] The description of the background art in this specification is for presenting the content of the present disclosure generally. The inventions of the currently named inventors are not to be regarded as prior art to the present disclosure, either explicitly or implicitly, in the aspects described in this background art section and in aspects of the description that do not fall within the prior art at the time of filing.

[0004] A substrate processing system may be used to perform etching, deposition, and / or other processes on a substrate such as a semiconductor wafer. Examples of processes that may be performed on the substrate include, but are not limited to, plasma - enhanced chemical vapor deposition (PECVD) processes, physical vapor deposition (PVD) processes, ion implantation processes, and / or other etching processes, deposition processes, and cleaning processes. As an example, during an etching process, the substrate may be placed on an electrostatic chuck (ESC) within the substrate processing system, and a thin film on the substrate is etched.

Summary of the Invention

[0005] An electrostatic chuck for a substrate processing system is provided. The electrostatic chuck is configured to electrostatically clamp a substrate and includes a top plate formed of ceramic, an intermediate layer disposed below the top plate, and a base plate formed of ceramic and disposed below the intermediate layer. The intermediate layer couples the top plate to the base plate. [[ID=3******]]

[0006] <00000********]] Other features include a ceramic purity of over 90% for the base plate. Other features include a ceramic purity of over 95% for the base plate. Other features include a ceramic purity of over 99.9% for the base plate.

[0007] In other features, the base plate includes a base layer and a protective coating layer placed on top of the base layer. The protective coating layer is positioned between the base layer and the intermediate layer.

[0008] In other features, the base plate includes a first part and a second part. The first part protrudes upward from the second part. The intermediate layer and top plate are positioned on top of the first part.

[0009] In other features, the base plate includes one or more gas passages. One or more gas passages are located beneath the top plate.

[0010] Other features include a base plate comprising a first layer and a second layer. The first layer is positioned above the second layer. The first layer includes a first gas flow path set. The second layer includes a second gas flow path set.

[0011] In other features, the base plate includes radio frequency (RF) electrodes. In other features, the base plate includes one or more gas channels. One or more RF electrodes are positioned above one or more gas channels in the base plate.

[0012] In other features, the base plate includes a first portion and a second portion. The first portion protrudes upward from the second portion. One or more RF electrodes are positioned radially outward of the first portion on the base plate.

[0013] In other features, the electrostatic chuck further includes an edge ring positioned on a base plate and at least partially radially outward from the top plate. The base plate includes a convex portion extending upward toward the top plate. The convex portion is at the center of the edge ring on the base plate. In other features, one or more RF electrodes are positioned below the edge ring on the base plate.

[0014] In other features, the electrostatic chuck further includes an edge ring positioned radially outward of the top plate, with its center located on the top plate. In other features, the electrostatic chuck further includes an edge ring positioned radially outward of the top plate, at least partially on the base plate. The edge ring includes radio frequency electrodes or electrostatic clamp electrodes. In other features, the top plate includes one or more electrostatic clamp electrodes. In other features, the top plate includes one or more heating elements. In other features, the base plate includes one or more DC electrodes.

[0015] In other features, the base plate includes refrigerant flow paths. In other features, at least one refrigerant flow path is in a bifilar configuration. In other features, at least one refrigerant flow path is in a single-filar configuration. In other features, the base plate includes a first layer and a second layer. The refrigerant flow paths include a first refrigerant flow path set and a second refrigerant flow path set. The first layer includes the first refrigerant flow path set. The second layer includes the second refrigerant flow path set.

[0016] In other features, the electrostatic chuck further includes a gas channel extending from the bottom of the base plate to the outlet of the top plate. The gas channel contains at least one porous medium. In other features, the electrostatic chuck further includes an annular seal positioned radially outward of the intermediate layer and providing protection to the intermediate layer.

[0017] Other features include a substrate processing system comprising a processing chamber, an electrostatic chuck, a temperature sensor, and a control module. The electrostatic chuck is located within the processing chamber and includes a temperature control element. The temperature sensor is located on at least one of the top plate and the base plate and is configured to detect the temperature of the top plate. The control module is configured to receive the output of the temperature sensor and to regulate the temperature of one or more temperature control elements by controlling the operation of an actuator based on the output of the temperature sensor to regulate the temperature of at least one of the top plate and the base plate.

[0018] In other features, one or more temperature control elements include at least one of a heating element, a gas flow path, and a refrigerant flow path, and the actuator is a power supply, a refrigerant pump, a gas pump, or a valve. In other features, a temperature sensor is located on the base plate and configured to detect the temperature of the base plate.

[0019] Other features of the substrate processing system include an edge ring and radio frequency electrodes. The edge ring is positioned on the base plate and at least partially radially outward from the top plate. The radio frequency electrodes are positioned below the edge ring on the base plate. A temperature sensor is positioned on the base plate and configured to detect the temperature of a region of the base plate. This region of the base plate is below the edge ring.

[0020] Further scope of application of this disclosure will become apparent from the modes for carrying out the invention, the claims, and the drawings. The modes for carrying out the invention and specific examples are for illustrative purposes only and are not intended to limit the scope of this disclosure. [Brief explanation of the drawing]

[0021] This disclosure will be better understood from the embodiments for carrying out the invention and the accompanying drawings.

[0022] [Figure 1]Functional block diagram showing an example of a substrate processing system incorporating an ESC according to an embodiment of the present disclosure.

[0023] [Figure 2] Cross-sectional side view showing an example of a part of an ESC incorporating a plate, a refrigerant flow path, a back gas flow path, an electrode, and a terminal according to an embodiment of the present disclosure.

[0024] [Figure 3] Cross-sectional side view showing an example of a part of an ESC incorporating a gas flow path having a porous plug, a sensor, a seal for an intermediate layer, an upper protruding arrangement of a base plate, and an electrostatic terminal according to an embodiment of the present disclosure.

[0025] [Figure 4] Cross-sectional side view showing an example of a part of an ESC representing a lift pin arrangement according to an embodiment of the present disclosure.

[0026] [Figure 5] Planar cross-sectional view showing an example of a refrigerant flow path layer of an ESC according to an embodiment of the present disclosure.

[0027] [Figure 6] Planar cross-sectional view showing an example of a refrigerant flow path layer of an ESC according to an embodiment of the present disclosure.

[0028] [Figure 7] Cross-sectional side view showing an example of a part of an ESC including an edge ring and representing a terminal of a radio frequency (RF) electrode of the edge ring according to an embodiment of the present disclosure.

[0029] [Figure 8] Cross-sectional side view showing an example of a part of an ESC representing a terminal of an RF electrode of a top plate of the ESC, or a gap between the top plate and the edge ring, and a peripheral arrangement of a seal for an intermediate layer and a base plate according to an embodiment of the present disclosure.

[0030] [Figure 9]A cross-sectional view showing an example of a portion of an ESC representing the terminals of the DC electrodes on the top plate of the ESC according to an embodiment of the present disclosure.

[0031] [Figure 10] A cross-sectional view showing an example of a portion of an ESC representing a gas flow path without a porous plug according to an embodiment of the present disclosure.

[0032] In drawings, reference numbers may be used multiple times to identify similar and / or identical elements. [Modes for carrying out the invention]

[0033] An ESC holds the substrate during substrate processing. The ESC holds the substrate in place using electrostatic force, for example, in a vacuum processing chamber. To electrostatically clamp the substrate onto the ESC while cooling the ESC, the ESC may have a two-plate configuration including a thin top plate made of a dielectric material and a bulk (or thick) base plate made of one or more metals and / or metal composites. Conventional top plates may be made of precisely controlled ceramic (i.e., having a ceramic purity of 90% or more) and include electrostatic electrodes to maintain the electrical properties of the top plate. Manufacturing precisely controlled thick ceramic plates is difficult; therefore, top plates are typically thin (e.g., 0.25 inches (0.635 centimeters) thick). Base plates can be easily and inexpensively manufactured by forming them from a metal or composite metal material (e.g., a compound of metal and ceramic). Forming and / or processing base plates from metal or composite metal materials to include coolant channels is inexpensive. It is also easy to join metal or composite metal plates by a brazing process.

[0034] The baseplate of the ESC may function as an electrode and may receive RF power. For example, the baseplate may include a base layer formed of aluminum and be connected to an RF power supply that receives RF power. The baseplate is usually coated with a protective coating, for example, a thin layer of ceramic, to provide a protective coating that prevents arc generation on the baseplate. The protective coating may be formed of alumina by an electrochemical anodizing process. A thicker coating layer may be formed by a thermal spraying process. Due to ever-increasing processing requirements, including higher RF voltages, a two-plate configuration can present several problems. High RF voltages and ion energies are required to etch or drill deep holes with high aspect ratios (e.g., 60:1) and / or to generate high plasma density to provide faster etching performance.

[0035] The ceramic coating on the baseplate may degrade under high RF voltages, potentially causing arc discharge to the baseplate. The ceramic coating may crack due to differences in thermal expansion coefficients between the ceramic coating and the base layer of the baseplate, which is formed from a metal or composite metal material. This can lead to arc discharge and limit the process operating range. Furthermore, because the top plate and baseplate are made of different materials, they have different thermal expansion coefficients. As a result, the top plate and baseplate expand and contract at different rates with temperature changes. This can lead to misalignment between the top plate, baseplate, and thermal stress, especially when subjected to large and / or rapid changes in operating temperature. Additionally, because the baseplate is made of a conductive material (i.e., metal or composite metal material), the baseplate acts as a single electrode, limiting the control of lateral RF voltage relative to the baseplate.

[0036] The examples described herein provide an ESC. The ESC includes a multi-plate arrangement that can handle high RF voltages without the problems described above. Each ESC includes a top plate and a base plate, both formed of ceramic. By forming both the top plate and the base plate of ceramic, the difference between the thermal expansion coefficients of the top plate and the base plate is minimized, so that the temperature mismatch between the top plate and the base plate is reduced compared to a conventional ESC with a two-plate arrangement. Also, by minimizing the difference in thermal expansion coefficients, the risk of high-voltage breakdown and / or cracking of the base plate coating layer due to thermal stress is reduced and / or eliminated compared to a conventional ESC. As a result, the usable operating temperature range of the ESC is extended.

[0037] Figure 1 shows a substrate processing system 100 incorporating ESC101. ESC101 may be configured similarly to or in analogous to any of the ESCs disclosed herein. While Figure 1 shows a capacitively coupled plasma (CCP) system, embodiments disclosed herein are applicable to trans-coupled plasma (TCP) systems, electron cyclotron resonance (ECR) plasma systems, inductively coupled plasma (ICP) systems, and / or other systems, as well as plasma sources including substrate supports. These embodiments are applicable to PVD processes, PECVD processes, chemically strengthened plasma vapor deposition (CEPVD) processes, ion implantation processes, plasma etching processes, and / or other etching, deposition, and cleaning processes.

[0038] ESC101 includes a top plate 102 and a base plate 103. Both plates 102 and 103 are made of ceramic and do not contain metal. In one embodiment, both plates 102 and 103 are formed of precisely controlled (i.e., having a purity of 90% or higher) ceramic. The purity of the ceramic may vary depending on the application. For example, the ceramic purity of plates 102 and 103 may be 90% or higher. In one embodiment, the ceramic purity of plates 102 and 103 is 95% or higher. In another embodiment, the ceramic purity of plates 102 and 103 is 99.9% or higher. As will be further described below, the base plate 103 may be entirely made of ceramic or may include a thin protective coating formed of a non-ceramic material. An example of a thin protective coating is shown in Figure 2. As some examples, plates 102 and 103 may be formed from alumina (Al2O3), aluminum nitride (AIN), silicon carbide (SiC), and / or other ceramic materials. A thin protective coating may be formed from AIN, yttria (Y2O3), zirconia (ZrO2), and / or other suitable materials. Plates 102, 103, other top plates and other base plates, and other features of the disclosed ESCs will be further described below with respect to the examples shown in Figures 1 to 10. The ESCs in Figures 1 to 10 are shown to have certain features and not others, but each ESC may be modified to have any of the features disclosed herein and in Figures 1 to 10.

[0039] Although ESC101 is shown mounted at the bottom of the processing chamber and not configured to rotate, ESC101 and other ESCs disclosed herein may be mounted at the bottom or top of the processing chamber and may be configured to rotate as a spin chuck during substrate processing. When mounted at the top of the processing chamber, the ESC may have a configuration similar to the configuration disclosed herein, but inverted and may include peripheral substrate support hardware, clamping hardware, and / or gripping hardware.

[0040] The substrate processing system 100 includes a processing chamber 104. The ESC 101 is surrounded by the processing chamber 104. The processing chamber 104 also surrounds other components, such as the upper electrode 105, and contains RF plasma. During operation, the substrate 107 is placed on the top plate 102 of the ESC 101 and is electrostatically clamped.

[0041] For illustrative purposes only, the upper electrode 105 may include a showerhead 109 for introducing and distributing gas. The showerhead 109 may include a stem portion 111 with one end connected to the upper surface of the processing chamber 104. The showerhead 109 is generally cylindrical and extends radially outward from the other end of the stem portion 111 at a distance from the upper surface of the processing chamber 104. The surface facing the substrate or the showerhead 109 includes holes through which process gas or purge gas flows. Alternatively, the upper electrode 105 may include a conductive plate, and the gas may be introduced by another means. Either or both of plates 102 and 103 may function as the lower electrode.

[0042] Either or both of plates 102 and 103 may include a temperature control element (TCE). As an example, Figure 1 shows plate 102 used as a heating plate, which includes a TCE 110. An intermediate layer 114 is placed between plate 102 and plate 103. The intermediate layer 114 may bond the top plate 102 to the base plate 103. As an example, the intermediate layer may be formed of an adhesive material suitable for bonding the top plate 102 to the base plate 103. The base plate 103 may include one or more gas channels 115 and / or one or more refrigerant channels 116 for flowing backside gas to the back surface of the substrate 107 and a refrigerant through the base plate 103.

[0043] The RF generation system 120 generates an RF voltage and outputs the RF voltage to the upper electrode 105 and the lower electrode (e.g., either or both of plates 102 and 103). Either the upper electrode 105 or the ESC 101 may be DC-grounded, AC-grounded, or at a stray potential. For illustrative purposes only, the RF generation system 120 may include one or more RF generators 122 (e.g., capacitively coupled plasma RF power generators, biased RF power generators, and / or other RF power generators) that generate the RF voltage supplied to the upper electrode 105 and / or ESC 101 by one or more matched distribution networks 124. Examples include a plasma RF generator 123, a biased RF generator 125, a plasma RF matched network 127, and a biased RF matched network 129. The plasma RF generator 123 may be a high-power RF generator that generates, for example, 6 to 10 kilowatts (kW) or more of power. The bias RF matching network supplies power to RF electrodes such as RF electrodes 131 and 133 on plates 102 and 103.

[0044] The gas delivery system 130 includes one or more gas sources 132-1, gas source 132-2, ..., and gas source 132-N (collectively, gas source 132) (where N is an integer greater than zero). Gas source 132 supplies one or more precursors and their gas mixtures. Gas source 132 may supply etching gas, carrier gas, and / or purge gas. Vaporized precursors may be used. Gas source 132 is connected to manifold 140 by valves 134-1, valve 134-2, ..., and valve 134-N (collectively, valve 134), as well as mass flow controllers 136-1, mass flow controllers 136-2, ..., and mass flow controllers 136-N (collectively, mass flow controller 136). The output of manifold 140 is supplied to processing chamber 104. For example, the output of manifold 140 is supplied to showerhead 109.

[0045] The substrate processing system 100 further includes a cooling system 141 which includes a temperature control device 142 which may be connected to the TCE 110. In one embodiment, the TCE 110 is not included. The temperature control device 142 is shown separately from the system controller 160, but may be implemented as part of the system controller 160. Either or both of plates 102 and 103 may include a plurality of temperature-controlled zones (for example, four zones, each having four temperature sensors).

[0046] The temperature control device 142 may control the operation and temperature of the TCE 110 to control the temperatures of plates 102 and 103, as well as the substrate (e.g., substrate 107). The temperature control device 142 and / or the system controller 160 may control the flow rate of back gas (e.g., helium) into the gas channel 115 for cooling the substrate by controlling the flow from one or more gas sources 132 to the gas channel 115. The temperature control device 142 may communicate with a refrigerant assembly 146 to control the flow of a first refrigerant (pressure and flow rate of the cooling fluid) through the channel 116. The first refrigerant assembly 146 may receive the cooling fluid from a reservoir (not shown). For example, the refrigerant assembly 146 may include a refrigerant pump and a reservoir. The temperature control device 142 operates the refrigerant assembly 146 to flow the refrigerant through the channel 116 to cool the base plate 103. The temperature control device 142 may control the rate at which the refrigerant flows and the temperature of the refrigerant. The temperature control device 142 controls the current supplied to the TCE 110, as well as the pressure and flow rate of the gas and / or coolant supplied to the channels 115 and 116, based on parameters detected from the sensor 143 in the processing chamber 104. The temperature sensor 143 may include a resistance thermometer, a thermocouple, a digital temperature sensor, and / or other suitable temperature sensor (e.g., several sensors shown in Figure 3 as temperature sensor 290). During the etching process, the substrate 107 may be heated to a predetermined temperature (e.g., 120°C) in the presence of a high-power plasma. The flow of gas and / or coolant through channels 115 and 116 reduces the temperature of the base plate 103 and reduces the temperature of the substrate 107 (e.g., cooling from 120°C to 80°C).

[0047] Valve 156 and pump 158 may be used to discharge the reactant from the processing chamber 104. The system controller 160 may control the components of the substrate processing system 100, including controlling the supply RF power level, supply gas pressure and flow rate, RF matching, etc. The system controller 160 controls the state of valve 156 and pump 158. A robot 170 may be used to deliver substrates onto the ESC 101 and to remove substrates from the ESC 101. For example, the robot 170 may transport substrates between the ESC 101 and the load lock 172. The robot 170 may be controlled by the system controller 160. The system controller 160 may control the operation of the load lock 172.

[0048] The power supply 180 provides power, including a high voltage, to the electrodes 182 in order to electrostatically clamp the substrate to the top plate 102. The power supply 180 may be controlled by the system controller 160.

[0049] Valves, gas pumps and / or refrigerant pumps, power supplies, RF generators, etc., may be called actuators. TCEs, gas flow paths, refrigerant flow paths, etc., may be called temperature control elements.

[0050] Referring similarly to Figure 2, a portion 200 of the ESC is shown, including a top plate 202, an intermediate layer 204, and a base plate (or bottom plate) 206. The top plate 202 is bonded to the base plate 206 via the intermediate layer 204. As shown in the figure, the base plate 206 may have a protective coating (or top layer) 208. As described above, plates 202 and 206 may be formed of ceramic, and the protective coating 208 may be formed of AIN, yttria (Y2O3), or zirconia (ZrO2). By forming both plates 202 and 206, as well as the protective coating 208, from ceramic and / or the same material, the difference between the thermal expansion coefficients of plates 202, 206, and the protective coating 208 is minimized. This minimizes and / or eliminates high-voltage breakdown and / or cracking of the protective coating 208. In other words, the corresponding standoff voltage increases.

[0051] In the example shown in the figure, the top plate 202 includes an electrostatic clamp electrode 210 that can receive power from a power supply 180. The electrostatic clamp electrode 210 may be connected to a terminal that can be connected to the power supply 180. An example of an insulating tower (sometimes called a “column”) including a terminal for the electrostatic clamp electrode is shown in Figure 3.

[0052] The base plate 206 includes a radio frequency (RF) electrode 212. The RF electrode 212 may receive power from a terminal 214 which may be connected to a bias RF matching network 129. The terminal 214 is located on an insulating tower 216 extending from the bottom of the base plate 206 to the RF electrode 212. The RF electrode 212 may be located near the top surface of the base plate 206 and / or within a predetermined distance from the top surface of the base plate 206. The RF electrode 212 may be arranged in different radial patterns across the base plate 206. The corresponding terminals may also be arranged in various patterns. For example, the terminals may be placed at equal intervals from each other, at equiradial distances from the center of the corresponding ESC, or at points along one or more circles.

[0053] RF electrodes 212 and other RF electrodes disclosed herein, which may be positioned on the top plate, base plate, and / or edge ring, may be controlled independently (i.e., receive power independently of each other) or collectively (i.e., two or more RF electrodes receive power from the same power source during the same period). When independently controlled, RF electrodes may be started and stopped at different rates and may receive different voltage and current levels. When RF electrodes are not independently powered, RF electrodes within the same group may be started and stopped simultaneously and receive the same voltage and current levels. Groups of RF electrodes may be controlled independently. The specified patterns and controls of the RF electrodes enhance control over the temperature of the entire top surface of the ESC during substrate processing, and thereby over the temperature of the substrate, and enhance control over the RF power and voltage across the top surface of the ESC and the substrate, thereby enhancing control over the etching and / or deposition processes.

[0054] One or more RF electrodes 212(212a) may be positioned on a portion 218 projecting upward from the base layer 219 of the base plate 206. The base plate 206 may include a protective coating 208 and a base layer 219. The base plate 206 may have one or more flat top surfaces and may include one or more steps. In the example shown, the base plate 206 has one step that descends from portion 218 to the base layer 219. Portion 218 has an uppermost (or top) surface 221, and the base layer 219 has an uppermost (or top) surface 223 at the flange 225. The roughness of surfaces 221 and 223 may be controlled during the formation of the base plate 206 to further control, for example, the transfer of thermal energy between the top plate 202 and the base plate 206. Portion 218 has an outer diameter smaller than the outer diameter of the base layer 219 and smaller than the outer diameter of the top plate 202. The top plate 202 has an outer diameter smaller than the outer diameter of the base plate 206. The specified diameter may vary depending on the application and the configuration of the corresponding components.

[0055] One or more RF electrodes 212(212b) may be positioned near the outer periphery of the base layer 219, as shown in the figure. The electrodes 212b may be positioned below an edge ring centered on portion 218 in the base layer 219. Portion 218 may be shaped (e.g., conical or a conical deformation) on the base plate 206 to center other chamber components (e.g., a second edge ring) and the gap between portion 218 and other chamber components may be minimized. An example of a second edge ring is shown in Figure 7.

[0056] One or more RF electrodes 212(212c) may be located in the base layer 219, not the portion 218, and may extend from a point radially inward of the outer periphery of the portion 218 to a point radially inward of the outer periphery of the base layer 219. The base layer 219 may comprise multiple layers. Each layer may have a corresponding refrigerant flow path and / or gas flow path. The RF electrodes 212 and / or other electrodes disclosed herein may be formed of, for example, tungsten (W), platinum (Pt), silver (Ag), palladium (Pd), and / or other conductive materials.

[0057] To provide the base plate with sufficient strength and durability and to accommodate the embedded channels disclosed herein having excellent heat transfer properties, the base plate 206 may be formed of ceramic composite layers that are laminated and sintered together to form a single structure. Each ceramic composite layer contains a mixture of ceramic and binder. For example, multiple thin (e.g., 1 mm thick) ceramic composites and binder layers may be laminated. The ceramic composite layers may be patterned to form gas channels 220 and refrigerant channels 222 when laminated. The resulting laminate is then fired in a furnace at a predetermined temperature for a predetermined period of time to allow the ceramic particles of the ceramic composite layers to sinter together, and to burn off the binder layer and / or other adhesives. The resulting base plate is then removed from the furnace.

[0058] The base plate 206 may include a gas channel 220 and a refrigerant channel 222. The gas channel 220 may receive gas from the manifold 140. The gas channel 220 may be arranged on the same radially extending plane and / or on the same one or more layers of the base plate 206, as shown in the figure. Alternatively, the gas channel 220 may be arranged on multiple radially extending planes and / or on different layers of the base plate 206. The gas channel 220 may be used to provide back-side gas to the back surface of the substrate. This is further illustrated in Figures 3 and 4. An example of a multi-layer arrangement of gas channels is shown in Figure 4.

[0059] The refrigerant flow paths 222 may be arranged on multiple radially extending planes and / or on different layers of the base plate 206, as shown in the figure. Alternatively, the refrigerant flow paths 222 may be arranged on the same radially extending plane or on the same one or more layers of the base plate 206. Each layer of the refrigerant flow paths 222 (three layers in the figure) may have bifilar or singlefilar refrigerant flow paths, examples of which are shown in Figures 5 and 6. The flow paths 220 and 222 are shown in a specific arrangement in the figure, but may be in other arrangements. Gas flow paths and / or refrigerant flow paths may be provided on any layer and / or any layer of the base plate 206.

[0060] Figure 3 shows a portion 250 of the ESC, including a top plate 252, an intermediate layer 254, and a base plate 256. The top plate 252 is bonded to the base plate 256 via the intermediate layer 254. The annular seal 257 may be positioned (i) between the outer circumference of the top plate 252 and the upper surface of the base layer 259 of the base plate 256, and (ii) covering the outer end 261 of the intermediate layer 254.

[0061] The top plate 252 includes an electrostatic clamp electrode 258 and a gas outlet 260. The gas outlet 260 receives backside gas from, for example, one or more gas channels (one gas channel 262 in the figure). Each of the one or more gas channels may include one or more porous media or plugs (e.g., porous plugs 264). The porous media and / or plugs may be co-fired with the ceramic plate. In one embodiment, the gas channels do not include porous plugs. The porous plugs contain small holes and function as intermediate buffers to prevent plasma generation in the gas channels. In the example shown, the first porous plug 264a is at the first end of the gas channel 262 and extends from a region within the base plate 256 and / or a region within a portion 266 of the base plate 256 through the intermediate layer 254 to a region within the top plate 260. The second porous plug 264b is at the second end of the gas channel 262 and is located at the bottom of the base plate 256.

[0062] The base plate 256 may include gas passages 270 and refrigerant passages 272, as described above. Each refrigerant passage 272 is connected to an input tower and an outlet tower within the base plate 256. An example of a tower 274 is illustrated.

[0063] The base plate 256 may include a tower 280 having a terminal (not shown) connected to one of the electrostatic clamp electrodes 258. The base plate 256 may further include one or more temperature sensors. An example of a temperature sensor 290 is shown, which is mounted on each tower 292. The temperature sensors may provide output signals to controllers 142 and 160. A first temperature sensor 290a is shown to detect the temperature within the top plate 252. A second temperature sensor 290b is shown to detect the temperature within the base layer 259. A third temperature sensor 290c is shown to detect the temperature near the outer edge of the base plate 256 below the RF electrode 294. Plates 252 and 256 may include any number of temperature sensors.

[0064] Figure 4 shows a portion 300 of the ESC, including a top plate 302, an intermediate layer 304, and a base plate 306. For example, the base plate 306 comprises a lift pin assembly 310 including a lift pin 312, a lift pin passage 313, and a gas passage 316. Any number of lift pin assemblies may be included in the ESC disclosed herein. The base plate 306 may include one or more layers of gas passages. The gas passages may be located above or below the refrigerant passages. For example, a first gas passage set 318 is shown above the refrigerant passage 320, and a second gas passage set 322 is shown below the refrigerant passage 320.

[0065] Figure 5 shows the refrigerant flow channel layer 400 of the ESC. The refrigerant flow channel layer 400 includes a bifilar arrangement of refrigerant flow channels 402. The refrigerant flow channels 402 include an inlet 404 and an outlet 406 located in the center of the refrigerant flow channel layer 400. The refrigerant flow channels 402 include a first section 407 and a second section 408. The first section 407 starts near the center of the refrigerant flow channel layer 400 and is wound in a circular coil pattern until it reaches the outer periphery of the refrigerant flow channel layer 400. The second section 408 extends from and along the first section 404 and returns from the outer periphery of the refrigerant flow channel layer 400 to a point near the center of the refrigerant flow channel layer 400. The cylindrical portions or all of sections 407 and 408 may extend parallel to each other.

[0066] Figure 6 shows the refrigerant flow channel layer 450 of the ESC. The refrigerant flow channel layer 450 includes a single-filer refrigerant flow channel 452. The refrigerant flow channel 452 includes a centrally located inlet 454 and an outlet 456 which may be located near the outer periphery of the refrigerant flow channel layer 450.

[0067] Several examples of refrigerant flow path configurations are shown in Figures 5 and 6. The ESCs disclosed herein may include other types of refrigerant flow path configurations. For example, an ESC may have a refrigerant flow path configuration having a center that is azimuthally symmetric with respect to an edge-type refrigerant flow.

[0068] Figure 7 shows a portion 500 of the ESC, including a top plate 502, an intermediate layer 504, a base plate 506, a first annular edge ring 508, and a second annular edge ring 509. The intermediate layer 504 may be positioned (i) between plate 502 and plate 506, and (ii) between the edge ring 508 and the base plate 506. The intermediate layer 504 may be formed of one or more materials having a high thermal conductivity (e.g., 0.5 to 0.4 watts per meter Kelvin (W / mK)).

[0069] The first annular edge ring 508 is centered on the top plate 502 and the base plate 506. The top plate 502 may be shaped (e.g., conical or a conical deformation) to center the second annular edge ring 509, minimizing the gap between the second annular edge ring 509 and the top plate 502. The radially inner end 511 of the second annular edge ring 509 may be shaped to align with the radially outer end 513 of the top plate 502. The first annular edge ring 508 may be made of ceramic and may include one or more electrodes that are mounted as RF electrodes and / or heating elements. The second annular edge ring 509 may be made of silicon and / or other suitable material, preventing at least a portion of the first annular edge ring 508 from being exposed to plasma.

[0070] An annular gap 510 may be located between the top plate 502 and the first annular edge ring 508. In one embodiment, an elastomer seal (e.g., an O-ring) may be located in the gap 510 and may be in contact with the outer circumferential surface 512 of the top plate 502, the upper surface 514 of the intermediate layer 504 or the upper surface 516 of the base plate 506, and the radially inward surface 518 of the edge ring 508. The top plate 502 may have an upper portion 520 projecting upward from the bottom 522 of the top plate 502. The upper portion 520 may include an electrostatic clamp electrode 524 and an RF electrode (one RF electrode 526 in the figure). The base plate 506 may include a gas channel (one gas channel 532 in the figure) and a refrigerant channel 534. Some of the refrigerant channels 534 may be located partially or entirely beneath the edge ring 508 in the base plate 506 to cool the edge ring 508.

[0071] The edge ring 508 may include one or more electrodes (one electrode 536 in the figure). An exemplary terminal 538 is shown, which provides power to electrode 536. The terminals disclosed herein may be of various types, for example, pogo pins. The terminals are configured to provide connections to the corresponding electrodes. Electrode 536 may be an RF electrode or an electrostatic clamp electrode. The edge ring 508 may have any number of RF electrodes and / or electrostatic clamp electrodes.

[0072] Figure 8 shows a portion 550 of the ESC, which includes a top plate 552, an intermediate layer 554, a base plate 556, and an edge ring 558. The ESC may include a seal 560 located at the outer peripheral edge 562 of the intermediate layer 554, between the outer peripheral edge 564 of the top plate 552 and the outer peripheral edge 566 of the bottom 568 of the base plate 556.

[0073] The annular gap 570 may be located between the top plate 552 and the edge ring 558. An elastomer seal (e.g., an O-ring) may be located in the gap 570. The convex portion 572 of the top plate 552 may include an electrostatic clamp electrode 573 and one or more RF electrodes 574. One or more RF electrodes 574 may receive power from the terminal 576. The edge ring 558 may include an electrode 578 which may be an RF electrode or an electrostatic clamp electrode.

[0074] Figure 9 shows a portion 600 of the ESC, including a top plate 602, an intermediate layer 604, and a base plate 606. The top plate 602 includes one or more DC electrodes 608. The DC electrodes 608 may receive power from a power source (e.g., power source 180 in Figure 1) via terminals such as terminal 610.

[0075] Figure 10 shows a portion 650 of the ESC, including a top plate 652, an intermediate layer 654, a base plate 656, and an edge ring 658. The base plate 656 includes a gas channel 660 that delivers back-side gas from a gas channel 660 through the intermediate layer 654 and the top plate 652 to a gas channel 662 that extends upward to an outlet 664. The gas channel 662 provides an example of a gas channel without porous plugs.

[0076] The above example includes a base plate made of ceramic and not metal. This eliminates high-voltage breakdown and / or cracking of the coating layer on the base plate. The plate of the disclosed ESC includes various electrode configurations having electrodes and channels embedded in various regions and layers of the plate for improved RF control and temperature control in the ESC, substrate and surrounding regions, as well as gas and refrigerant channel configurations. Because the base plate of the ESC is made of ceramic, the base plate can include any number of electrodes, such as RF electrodes for improved RF control of the entire substrate. Also, because ceramics have lower thermal conductivity than metals, and / or due to limitations in the manufacturing process of ceramic material lamination sintering, the base plate is disclosed to have multiple layers of refrigerant channels to increase the cooling contact area.

[0077] The foregoing is essentially descriptive and is not intended to limit the Disclosure, its application, or its use. The broad teachings of the Disclosure can be implemented in various forms. Thus, while the Disclosure includes certain examples, the true scope of the Disclosure should not be limited to that extent, as other modifications will become apparent upon consideration of the drawings, specification, and the following claims. One or more steps within the Method may be performed in a different order (or simultaneously) without altering the principles of the Disclosure. Furthermore, while each embodiment has been described above as having certain features, one or more of those features described in relation to the embodiments of the Disclosure may be implemented in other embodiments and / or in combination with features of other embodiments (even if such combination is not specified). In other words, the embodiments described are not mutually exclusive, and rearrangements of one or more embodiments remain within the scope of the Disclosure.

[0078] Spatial and functional relationships between elements (e.g., between modules, between circuit elements, between semiconductor layers, etc.) are described using a variety of terms, including “connected,” “engaged,” “joined,” “adjacent,” “nearby,” “above,” “upward,” “downward,” and “positioned.” When a relationship between a first element and a second element is described in the above disclosure, unless it is explicitly stated to be “direct,” the relationship may be a direct relationship in which no other intervening elements exist between the first and second elements, or it may be an indirect relationship in which one or more intervening elements exist (spatially or functionally) between the first and second elements. The expression “at least one of A, B, and C” as used herein should be interpreted as meaning the logic using the non-exclusive logic OR (A OR B OR C), and not as “at least one of A, at least one of B, and at least one of C.”

[0079] In some embodiments, the controller is part of a system which may be part of the examples described above. Such a system may comprise a semiconductor processing apparatus including processing tools, chambers, processing platforms, and / or specific processing components (such as wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of semiconductor wafers or substrates. The electronics may mean “controllers” that can control various components or sub-components of the system. Depending on the processing conditions and / or the type of system, the controller may be programmed to control any of the processes disclosed herein, including process gas delivery, temperature setting (e.g., heating and / or cooling), pressure setting, vacuum setting, power setting, radio frequency (RF) generator setting, RF matching circuit setting, frequency setting, flow rate setting, fluid delivery setting, position operation setting, tools and other transport tools, and / or wafer transport to a load lock connected to or coupled to a particular system.

[0080] Generally, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive and issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. Integrated circuits may include a firmware-type chip that stores program instructions, a chip defined as a digital signal processor (DSP), an application-specific integrated circuit (ASIC), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). Program instructions are instructions that are communicated to the controller in the form of various individual settings (or program files) and may define operating parameters for executing a particular process on or for a semiconductor wafer or for a system. In some embodiments, the operating parameters may be part of a recipe defined by a process engineer to realize one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or one or more processing steps during the fabrication of a wafer die.

[0081] In some embodiments, the controller may be part of a computer integrated with or coupled to the system, or otherwise networked to the system, or a combination thereof, or coupled to such a computer. For example, the controller may reside in a “cloud” enabling remote access to wafer processing, or may be all or part of a fab host computer system. The computer may enable remote access to the system to monitor the progress of fabrication operations, investigate the history of past fabrication operations, investigate trends or performance criteria from multiple fabrication operations, modify parameters of the current operation, set up subsequent processing steps for the current operation, or start a new process. In some examples, a remote computer (e.g., a server) may provide process recipes to the system via a network that may include a local network or the internet. The remote computer may include a user interface that enables the entry or programming of parameters and / or settings that are then transmitted from the remote computer to the system. In some examples, the controller receives instructions in a data format that specify parameters for each processing step performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed and the type of tool that the controller is configured to connect to or control. Therefore, as described above, the controllers may be distributed by, for example, including one or more individual controllers that are networked together, or by cooperating toward a common purpose such as the processes and controls described herein. An example of controllers distributed toward such a purpose would be one or more integrated circuits on a chamber that are located remotely (for example, at the platform level or as part of a remote computer) and communicate with one or more integrated circuits that cooperate to control the processes in the chamber.

[0082] The exemplary system may include a plasma etching chamber or plasma etching module, a deposition chamber or deposition module, a spin rinse chamber or spin rinse module, a metal plating chamber or metal plating module, a cleaning chamber or cleaning module, a bevel edge etching chamber or bevel edge etching module, a physical vapor deposition (PVD) chamber or PVD module, a chemical vapor deposition (CVD) chamber or CVD module, an atomic layer deposition (ALD) chamber or ALD module, an atomic layer etching (ALE) chamber or ALE module, an ion implantation chamber or ion implantation module, a track chamber or track module, and other semiconductor processing systems that may be associated with or used in the fabrication and / or manufacture of semiconductor wafers.

[0083] As described above, depending on the process steps performed by the tool, the controller may communicate with one or more of the following: other tool circuits or tool modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools installed throughout the factory, a main computer, another controller, or tools used for material handling to load and unload wafer containers to and from tool locations and / or load ports in a semiconductor manufacturing plant.

Claims

1. An electrostatic chuck for a substrate processing system, A top plate made of ceramic is configured to be electrostatically clamped to the substrate, An intermediate layer positioned below the top plate, The intermediate layer is positioned below the base plate, which is made of ceramic. The intermediate layer is an electrostatic chuck that connects the top plate to the base plate.

2. The electrostatic chuck according to claim 1, An electrostatic chuck in which the ceramic purity of the base plate is 90% or higher.

3. The electrostatic chuck according to claim 1, An electrostatic chuck wherein the ceramic purity of the base plate is 95% or higher.

4. The electrostatic chuck according to claim 1, An electrostatic chuck in which the ceramic purity of the base plate is 99.9% or higher.

5. The electrostatic chuck according to claim 1, The aforementioned base plate is Base layer and The base layer comprises a protective coating layer disposed on the base layer, The protective coating layer is an electrostatic chuck disposed between the base layer and the intermediate layer.

6. The electrostatic chuck according to claim 1, The base plate comprises a first portion and a second portion, The first portion protrudes upward from the second portion, The intermediate layer and the top plate are an electrostatic chuck positioned in the first portion.

7. The electrostatic chuck according to claim 1, The base plate is provided with one or more gas passages, The one or more gas passages are electrostatic chucks located below the top plate.

8. The electrostatic chuck according to claim 1, The base plate comprises a first layer and a second layer, The first layer is positioned above the second layer. The first layer comprises a first gas flow path set, The second layer is an electrostatic chuck equipped with a second gas flow set.

9. The electrostatic chuck according to claim 1, The base plate is an electrostatic chuck equipped with multiple radio frequency (RF) electrodes.

10. The electrostatic chuck according to claim 9, The base plate is provided with one or more gas passages, An electrostatic chuck in which one or more of the plurality of RF electrodes are positioned above one or more gas flow paths on the base plate.

11. The electrostatic chuck according to claim 9, The base plate comprises a first portion and a second portion, The first portion protrudes upward from the second portion, One or more of the plurality of RF electrodes are arranged radially outward from the first portion on the base plate, forming an electrostatic chuck.

12. The electrostatic chuck according to claim 9, further, The base plate is provided with an edge ring that is at least partially positioned radially outward from the top plate, The base plate is provided with a protrusion that extends upward toward the top plate, The aforementioned protrusion is an electrostatic chuck located at the center of the edge ring on the base plate.

13. The electrostatic chuck according to claim 12, One or more of the plurality of RF electrodes are an electrostatic chuck positioned below the edge ring on the base plate.

14. The electrostatic chuck according to claim 1, further, An electrostatic chuck comprising an edge ring positioned radially outward of the top plate, with the top plate being the center of the edge ring, which is positioned on the base plate.

15. The electrostatic chuck according to claim 1, further, The base plate is provided with an edge ring that is at least partially positioned radially outward from the top plate, The edge ring is an electrostatic chuck equipped with a radio frequency electrode or an electrostatic clamp electrode.

16. The electrostatic chuck according to claim 1, The top plate is an electrostatic chuck equipped with one or more electrostatic clamp electrodes.

17. The electrostatic chuck according to claim 1, The top plate is an electrostatic chuck equipped with one or more heating elements.

18. The electrostatic chuck according to claim 1, The base plate is an electrostatic chuck equipped with one or more DC electrodes.

19. The electrostatic chuck according to claim 1, The base plate is an electrostatic chuck equipped with multiple refrigerant passages.

20. The electrostatic chuck according to claim 19, An electrostatic chuck in which at least one of the plurality of refrigerant flow paths is in a bifilar arrangement.

21. The electrostatic chuck according to claim 19, An electrostatic chuck in which at least one of the plurality of refrigerant flow paths is in a single-filer arrangement.

22. The electrostatic chuck according to claim 19, The base plate comprises a first layer and a second layer, The plurality of refrigerant flow paths include a first refrigerant flow path set and a second refrigerant flow path set, The first layer comprises the first refrigerant flow path set, The second layer is an electrostatic chuck comprising the second refrigerant flow path set.

23. The electrostatic chuck according to claim 1, further, The base plate is provided with a gas flow path extending from the bottom to the outlet of the top plate, The gas flow path is an electrostatic chuck containing at least one porous medium.

24. The electrostatic chuck according to claim 1, further, An electrostatic chuck comprising an annular seal positioned radially outward of the intermediate layer to provide protection for the intermediate layer.

25. A substrate processing system, Processing chamber and The electrostatic chuck according to claim 1, which is disposed within the processing chamber and includes a temperature control element, A temperature sensor is disposed on at least one of the top plate and the base plate and configured to detect the temperature of the top plate, A control module configured to receive the output of the temperature sensor, which controls the operation of an actuator based on the output of the temperature sensor to adjust the temperature of one or more temperature control elements in order to adjust the temperature of at least one of the top plate and the base plate, A substrate processing system comprising the above.

26. A substrate processing system according to claim 25, The one or more temperature control elements include at least one of a heating element, a gas flow path, and a refrigerant flow path. The actuator is a power supply, a refrigerant pump, a gas pump, or a valve in a substrate processing system.

27. A substrate processing system according to claim 25, A substrate processing system in which the temperature sensor is placed on the base plate and configured to detect the temperature of the base plate.

28. A substrate processing system according to claim 25, further, An edge ring is disposed on the base plate and at least partially located radially outward from the top plate, The base plate comprises a radio frequency electrode positioned below the edge ring, The temperature sensor is positioned on the base plate and configured to detect the temperature of a region of the base plate. A substrate processing system wherein the region of the base plate is below the edge ring.

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